Local Anesthetic Thoracoscopy for Undiagnosed Pleural Effusion

Abstract

Local anesthetic thoracoscopy (LAT) is a minimally invasive diagnostic procedure gaining recognition among chest physicians for managing undiagnosed pleural effusions. This single-port procedure is conducted with the patient under mild sedation and involves a contralateral decubitus position. It is performed in a sterile setting, typically a bronchoscopy suite or surgical theater, by a single operator with support from a procedure-focused nurse and a patient-focused nurse.

The procedure begins with a thoracic ultrasound to determine the optimal entry point, usually in the IV-V intercostal space along the midaxillary line. Lidocaine/mepivacaine, with or without adrenaline, is used to anesthetize the skin, thoracic wall layers, and parietal pleura. A designated trocar and cannula are inserted through a 10 mm incision, reaching the pleural cavity with gentle rotation. The thoracoscope is introduced through the cannula for systematic inspection of the pleural cavity from the apex to the diaphragm. Biopsies (typically six to ten) of suspicious parietal pleura lesions are obtained for histopathological evaluation and, when necessary, microbiological analysis. Biopsies of the visceral pleura are generally avoided due to the risk of bleeding or air leaks. Talc poudrage may be performed before inserting a chest tube or indwelling pleural catheter through the cannula. The skin incision is sutured, and intrapleural air is removed using a three-compartment or digital chest drainage system. The chest tube is removed once there is no airflow, and the lung has satisfactorily re-expanded. Patients are usually discharged after 2-4 h of observation and followed up on an outpatient basis. Successful LAT relies on careful patient selection, preparation, and management, as well as operator education, to ensure safety and a high diagnostic yield.